In a reactive ion etching (RIE) process using a resist in a semiconductor process, when a selection ratio of resist for a material to be etched is small, an etching amount of the resist increases more than necessary.
During the RIE using the resist as a mask, unevenness occurs in etching due to non-uniformity in hardness of the resist, non-uniformity of a plasma density during the RIE, and the like, and thus a width or a shape of a pattern is different in each region. As a result, roughness occurs in a pattern including the resist and a material to be subjected to the RIE.
An example of related art includes JP-A-2003-273291.